Resonant frequency measurements as an alternative to phase-selective A.C. polarography in tensammetry and pseudocapacitance determinations

A new method is proposed for the determination of the double-layer capacitance and pseudocapacitance of electrochemical cells. The method is based on the measurement of the resonant frequency of the circuit consisting of the electrochemical cell connected in series with a standard inductor. The performance of the method is demonstrated with double-layer capacitance measurements at the dropping mercury electrode in 1 M KCl and butanol-1/1 M KCl mixtures and with the determination of heterogeneous charge-transfer rate constants ranging from 10−2 to 10−5 m s−1.